Term
| Patent Ductus Arteriosus (PDA) |
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Definition
Closure of the DA is prolonged (>5 days)
-May be associated with hypoplasia or abnormal distribution of ductus sm. muscle,
-Or may be due to excess elastic tissue in the ductus wall i.e. sm. musc. can’t contract to close the DA |
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Term
| Atrial Septal Defect (ASD) |
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Definition
Hole in septum between L and R atria, mostly due to incomplete closure of foramen ovale
-may get L-R shunt |
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Term
| Ventricular Septal Defect (VSD) |
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Definition
A defect in the inter-ventricular septum between L and R ventricles
Majority are upper mem. portion of vent. septum below aortic / AV valves
Shunt usually L-to-R |
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Term
| Atrioventricular Septal Defect |
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Definition
A hole in the septum resulting in incomplete separation of L and R atria and Land R ventricles
Resuls in Single AV valve and so mixing of blood from syst. and pul. sys. |
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Term
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Definition
Narrowing of the pul. valve and obstruction to BF– may be just before or just after
-narrowing od valve itself is most common |
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Term
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Definition
| Lack of formation of pul. valve - v. uncommon |
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Term
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Definition
Narrowing of the aortic valve , obstruction to BF
-subvalvular most common |
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Term
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Definition
Abnormal development of the AV valve/s
-mitral (LAV) valve dysplasia is mMost common congenital cardiac anomaly in cats |
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Term
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Definition
Failure to fully close and therefore leakiness of the valve
Potential consequence of AV valve dysplasia |
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Term
| AV valvular haematomas (haematocysts) and lymphocysts |
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Definition
| Blood or lymph filled cystic structures up to ~1cm diameter on the margins of the AV valves |
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Term
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Definition
A vascular ring that encircles the oesophagus and/or trachea
Due to abnormal development of aortic arches and gr. vessels |
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Term
| Persistent Right Aortic Arch (PRAA) |
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Definition
Most common vasc. ring anomaly
Aorta develops from the R 4th aortic arch instead of the L
The aorta, pul. art. base of H and ligamentum arteriosum form a vasc. ring which oes and poss. trachea pass through |
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Term
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Definition
| Single art. trunk supplies sys., pul., coronary BF. Also a VSD present. |
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Term
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Definition
4 components:
-VSD
-Pul. stenosis
-R. vent. hypert.
-Dextraposition of aorta (overriding)
Results in R-to-L shunt from R vent. through septal defect into overriding aorta
(English Bulldogs predisposed) |
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Term
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Definition
| H completely or partly positioned out of thoracic cavity - most freq. in cattle |
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Term
| Excessive moderator bands in L vent in cats |
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Definition
(Moderator bands only in R vent. in cat.)
Moderator bands contain conducting fibres from vent wall to septum – bands in L can lead to impaired vent. filling and H failure in later life |
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Term
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Definition
Most common type of pericarditis
Fibrinous inflam. w. exudate resulting in the accumulation of fibrin in the pericardial sac - “bread and butter”
Often by haematogoneous infection |
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Term
| Suppurative / purulent pericarditis |
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Definition
Accumulation of pus in the pericardial sac - usually due to infection with pyogenic bact.
-Most common in cattle with traumatic reticulitis |
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Term
| Constrictive pericarditis |
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Definition
Pericardial sac is expanded by organising GT and/or formation of fibrous pericardial adhesion
Results in compromised cardiac filling and function, may result in H failure |
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Term
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Definition
Accumulation of serous fluid (transudate) within the pericardial sac
Usually as a result of dz. with generalised oedema. |
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Term
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Definition
| Presence of whole blood in the pericardial sac |
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Term
| Haemorrhagic pericardial effusion |
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Definition
Fluid and blood in the pericardial sac
i.e. not pure blood |
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Term
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Definition
Accumulation of blood or excess fluid (inflam. or not) in the pericardial sac which causes compression of the H
Results in reduced cardiac filling and output, hypotension and shock |
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Term
| Serous atrophy of pericardial fat |
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Definition
Serous atrophy of pericard fat (normally contains variable amount of fat) due to rapid mobilisation of fat from pericardium
e.g. during starvation/cachexia |
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Term
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Definition
-Most common type of endocarditis
-Mitral and aortic more common i.e. L, although cattle more on RAV
-Essentially a thrombus attached to the valve "cauliflower like"
Layers of fibrin and blood embedded with bact. overlying an organising layer of GT and inflame cells (macro. and neutro) |
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Term
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Definition
Endocarditis affecting the inside wall of H chambers – lesions develop on free margins of valve leaflets
-Nearly always by bacterial agents |
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Term
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Definition
Mainly L atrium, poss. L vent./ large elastic aa.
Caused by acute kidney failure resulting in uraemia
Healing of the ulcerated regions can result in formation of raised fibrous and mineralized plaques/nodules |
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Term
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Definition
Nodular distortion of the valve leaflets (w. smooth surface), mainly affecting one or both AV (normally mitral/LAV)
Rarely affects pul/aortic valves.
-Common in dogs, esp males, esp small/toy breeds e.g. CKCS |
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Term
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Definition
Irregular foci of endocardial fibrosis Due to trauma caused to endocardium.
Endocardiosis most common cause. |
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Term
| Endocardial fibrosis and mineralization |
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Definition
Fibrosis with/without minerilazation of the endocardium.
NB: animals euthanized with barbiturates can have barbiturate salt deposition in H – do not confuse! Barbiturates will dissolve in formulin |
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Term
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Definition
Atrial thrombosis may occur in dilated atria where there is dec. BF or stasis.
In cats (less dogs) may get thrombosis of L atrium with hypert. cardiomyopathy |
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Term
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Definition
Idiopathic and occurs in hypertrophic cardiacmyopathy
Irreversible change |
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Term
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Definition
Usually an adaptive response to inc. functional demand due to incr. mechanical stimulation (stretching of myocard) or trophic stimulation by various neuroendocrine H
-Usually reversible if the cause is removed |
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Term
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Definition
-Thicker than normal walls and chambers may appear smaller than normal.
-Thicker myocytes: incr. sarcomeres arranged in parallel
-Associated with conditions that need to generate incr. systolic P to overcome incr. afterload/P overload |
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Term
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Definition
-Normal or thin walls with dilated chambers.
-Elongated myocytes: inc. sarcomeres arranged in series
-Associated with conditions that cause inc. blood vol. in chambers (vol. overload)
-May develop as a late/ terminal change in conditions that initially cause conc. hypert |
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Term
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Definition
Necrosis / loss of cardiac tissue
(remember can’t replace/ regenerate myocytes) |
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Term
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Definition
| Increase number of lipocytes seen in the myocardium, in obese animals |
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Term
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Definition
| Cells swell due to injury |
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Term
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Definition
| Intra-cytoplasmic accumulation of triglycerides. Not usually uniform within the myocardium. |
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Term
| Hypertrophic cardiomyopathy (HCM) |
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Definition
-IDIOPATHIC thickening of the heart wall esp L ventricle and intervent. septum
-Results in small L vent. chamber
-Left atrium is normally dilated
-Mostly in cats, more in males.
-May cause sudden death – one of most common causes of non-traumatic sudden death in cats
-In cats may see "saddle thrombosis" |
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Term
| Dilated cardiomyopathy (DCM) |
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Definition
-Isiopathic dilation of all cardiac chambers or predom. L
-H enlarged, rounded with flabby thin walls
-Mostly in dogs esp. large breeds and males. |
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Term
| Arrythmogenic R ventricular cardiomyopathy |
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Definition
-type of DCM - rare
-idiopathic gradual replacement and thinning of R vent. myocard. with fibrous and fatty tissue
-Similar milder changes may affect the L
-results in dec. contracility |
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Term
| Restrictive cardiomyopathy |
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Definition
Idiopathic impaired ability of H chambers to expand during vent. filling
-Most commonly due to loss of compliance – walls become rigid with dec. flexibility
-in cats, esp males |
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Term
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Definition
Heart attack
May result from thrombosis/ embolism of coronary aa |
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Term
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Definition
| Tumour arising from aortic body i.e. chemo-R tumour. May be benign or malignant |
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Term
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Definition
| failure to maintain sufficient CO to meet the demands of the body tissues (forward failure) or can only do when cardiac filling pressures are abnormally high (backward failure) or a combination. May be acute or chronic |
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Term
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Definition
| The cardiac output drops suddenly and by a large amount |
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Term
| Chronic (congestive) heart failure |
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Definition
Inability of the heart to maintain adequate CO to deal with venous return.
One or both vent. fails to pump blood out and/or fails to fill, therefore:
-dec CO (forward failure)
-damming back of blood (congestion) and inc. P in venous circ. (backward failure) |
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Term
Chronic (congestive) heart failure
(systolic dysfunction) |
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Definition
| One or both vent. fails to pump blood out/ dec. ejection of blood |
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Term
Chronic (congestive) heart failure
(diastolic dysfunction) |
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Definition
One or both vent. fails to fill
/ impaired filling w. blood |
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Term
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Definition
Localised dilation/ widening of a part of vessel due to thickening or weakening of the wall.
Most commonly in aa., esp large/elastic e.g. aorta |
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Term
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Definition
| Blood is able to enter the tunica media and split or dissect along the wall |
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Term
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Definition
-Hypertrophy and hyperplasia of tunica media sm. muscle.
-Usually seen in musc. aa.
-As a response to prolonged inc. art. P or vol. overload |
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Term
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Definition
-Hardening of the aa.
-Develops with incr. age – rel. common when older |
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Term
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Definition
Accumulation of fatty deposits and fibrous tissue in the vessel walls resulting in narrowing of vessel lumen
-uncommon in animals |
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Term
| Arterial medial calcification |
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Definition
| Affected aa have firm walls or raised, hard, white intimal plaques, quite gritty |
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Term
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Definition
| Calcium and iron deposits in cerebral aa. in aged horses - incidental |
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Term
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Definition
-Endothelial damage and fibrin formation and deposition in vasc. wall
-May occur is acute degen. and inflam. conditions affecting small aa and arterioles (vasculitis)
e.g. dogs w. uraemia due to acute kidney failure / pigs w. Se/vit E deficiency
-Fibrin magenta w. PAS stain |
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Term
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Definition
| An inappropriate intravascular coagulation/ clotting (platelet aggregation and fibrin formation). |
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Term
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Definition
-Occulsion of aa. by foreign material within the blood stream.
-May be septic or bland
-Most arise from thrombi.
-Also air, fat, fibrocartilage, neoplastic cells, bact., parasites |
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Term
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Definition
| Reduction in blood supply to a tissue |
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Term
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Definition
-Region of necrosis (normally coagulative) caused by ischaemia -Most commonly due to blockage of an end aa. by embolism /thrombus
-May occur to external compression e.g. torsion of a bowel loop, severe traumatic compression |
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Term
| Haemangioma / Haemangiosarcoma |
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Definition
| Tumours arising from endothelium of b.v. i.e. the inner most layer |
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Term
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Definition
-An anomalous vasc. connection allows blood to bypass the liver through a shunt from portal ven. syst. to systemic ven. syst.
-results in hepatic encephalopathy |
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Term
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Definition
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Term
| Aplasia / hypoplasia of lymphatic vessels |
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Definition
| -defective development of lymphatic vessels, can cause lymphoedema |
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Term
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Definition
-Dilation of lymphatic vessels
-Often present on sites of severe inflam.
-Can be caused by neoplastic dz – if block vessels by infiltration / compression |
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Term
| Interstitial lymphangectasia |
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Definition
Huge dilation of lacteals and distension of intestinal and mesenteric lymphatic ducts
-can result in protein losing enteropathy (PLE) |
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Term
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Definition
| inflam of lymphatic vessels |
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Term
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Definition
Rare neoplasms of lymphatic endothelium.
Often soft, poorly demarcated masses |
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